Machine for cold heading wire



1, 1967 E. E. DABNEY ET AL 3,333,456

MACHINE FOR COLD READING WIRE Filed Dec. 28, 1964 4 Sheets-Sheet l I 'INVENTORS. EUGENE E. DABNEV .JAMES R. FIELDS A T rap/v5 Aug. 1, 1967 E. E. DABNEY ET AL 3,333,456

MACHINE F 'OR COLD HEADING WIRE Filed Dec. 28, 1964 4 Sheets-Sheet 2 INVENTORS. g EUGENE E. DABNEY JAMES R. FIELDS wa ed,

1, 1967 E. E. DABNEY ET AL 3,333,456

v MACHINE FOR COLD HEADING WIRE Filed Dec. 28, 1964 4 Sheets-Sheet 3 34. I I I I H .I 37 II 1 l l l' 1. ////[/Al I (3 I I "a I I I l l i INVENTORS EUGENE E. DAB/V5) TTOR EY Aug. 1 1 967 Filed Dec.

IIIIIIIII/ E. E. DABNEY ET AL MACHINE FOR COLD HEADING WIRE 4 Sheets-Sheet 4 y/ x ////V/ 4 I Ill/l/VI/l III II [IA INVENTORS. EUGENE E. DABNEY JAMES R. FIELDS ATmRA/ r United States Patent 3,333,456 MACHINE FOR COLD HEADING WIRE Eugene E. Dabney and James R. Fields, Corpus Christi,

Tex., assignors to The Prescon Corporation, a corporation of Texas Filed Dec. 28, 1964, Ser. No. 421,566 6 Claims. (Cl. 72-453) ABSTRACT OF THE DISCLOSURE A machine for heading wire by a cold forming method which has a pair of hydraulic pressure operated clamping jaws that are horizontally elongated and have open ended wire receiving grooves extending lengthwise thereof. The wire clamping jaws are recessed at one end and the heading die, is recessed to together form the head on the wire. The heading die is hydraulic pressure operated. The die has a flat end face that engages flat end faces on the gripping jaws to limit heading movement of the die. The movements of the pistons in the hydraulic cylinders for operating the gripping jaws and the heading die are controlled by a sequence valve, a solenoid valve that is moved to position to supply hydraulic fluid to the cylinders by a manually closed switch, a relief valve for reducing the pressure to atmospheric in the supply line and a pressure controlled switch operating apparatus for opening the circuit to the solenoid valve. The solenoid valve is supplied with hydraulic fluid to operate it through a venturi inserted between the main supply line and the switch operating member. The pistons are returned to starting position by hydraulic fluid put under pressure by the movement of the pistons into their extreme operating position through a closed circuit from a closed tank that has hydraulic fluid in the bottom part thereof and air in the top part thereof with the connection between the cylinders and this tank near the bottom of the tank.

Our invention relates to a heading machine, and more particularly to a cold heading machine for high tensile strength steel wires.

It is a purpose of our invention to provide means for holding a wire so that a head can be formed thereon by a cold forming method that is of such a character that the holding means will not in any manner cut or bite into the wire to reduce the tensile strength thereof at the places where the holding means engage therewith.

More specifically our invention comprises a pair of work clamping jaws, one of which is stationary and the other of which is movable toward and away from the stationary clamping jaw, which jaws are provided with grooves therein for lengthwise receiving the wire or similar member that is to be headed therein and to provide means for moving said movable jaw into clamping engagment with the wire or similar member and hold it in clamping engagement with the wire in cooperation with the stationary jaw, so that it will remain in position against any movement longitudinally of the wire during the heading operation due to the pressure exerted by the grooved jaws on the wire. In order to provide for a suitable holding force exerted by the jaws, suitable hydraulic means comprising a cylinder and piston operating therein with which the movable jaw is connected to move therewith, is provided, which is provided with suitable means for controlling the hydraulic pressure to exert the desired holding pressure on the wire or similar member when the jaws are in clam-ping engagement with the wire located in the grooves therein.

It is a further purpose of our invention to provide, in a heading machine of the above referred to character, a

3,333,455 Patented Aug. 1, 1967 pair of work clamping jaws, having the above referred to characteristics and moved into and out of clamping engagement in the above referred to manner, wire heading means comprising a heading die that moves in a direction parallel to the length of said grooves toward and away from one end of said clamping jaws into and out of heading position, hydraulic means for moving said die, and means for controlling the supply of hydraulic fluid so as to first move the movable jaw into cooperative clamping position with respect to the stationary jaw and hold it in its clam-ping position with a predetermined clamping pressure before movement of the heading die toward heading position begins, the clamping jaws being each provided with a stationary heading die portion at the end thereof toward which said movable die moves.

It is another specific purpose of our invention to pr vide, in a device of the above mentioned character, means for supporting a wire or similar member when the clamping jaws are in a separated position so that said wire is in alignment with the grooves in said clamping jaws ready to be received therein when said movable jaw moves into Wire clamping position relative to the stationary jaw, and to provide elongated clamping jaws that have grooves therein that extend lengthwise thereof, =but terminate short of the ends of said jaws at which said stationary heading die portions are located, and to provide guiding means for said movable die so as to assure the proper location of the movable heading die relative to the extending or projecting portion of the wire or similar member held between said clamping jaws from which the head on said wire or similar member is to be formed.

It is a further purpose of our invention to provide, in a heading device of the above mentioned character, means for controlling the Supply of hydraulic fluid to the hydraulic means for moving the movable clamping jaw and the hydraulic means for movement of the movable die of the heading dies, so that the hydraulic fluid that is fed to the hydraulic cylinder for moving the clamping jaW, builds up to a suflicient pressure to firmly clamp the wire, before any movement of the heading die takes place, said controlling means comprising a valve that provides for the entrance of hydraulic fluid into the hydraulic cylinder, 1

that moves the heading die, only after the desired maximum pressure is built up in the hydraulic cylinder controlling movement of the clamping jaw.

It is a further purpose of our invention to provide means for relieving the hydraulic pressure in the system after a predetermined maximum pressure has been reached, and means for returning the pistons in the hydraulic cylinders to their starting position, comprising a container for hydraulic fluid and air connected with the hy draulic cylinders so that the compression of the air in the container will force hydraulic fluid therefrom into the hydraulic cylinders to return the pistons in the cylinders to their starting position.

Other objects and advantages of our invention will appear as the description of the drawings proceeds. We desire to have it understood, however, that we do not intend to limit ourselves to the particular details shown or described, except as defined in the claims.

In the drawings:

FIG. 1 is a plan view of our improved heading machine.

FIG. 2 is a section taken on the line 22 of FIG. 1 on an enlarged scale.

FIG. 3 is a sectional view through our improved heading machine, taken on the line 3-3 of FIG. 1, with the clamping jaws in open position.

FIG. 4 is an enlarged detail fragmentary sectional view through the clamping jaws and associated parts.

FIG. Sis a fragmentary sectional view through the end of the clamping jaws adjacent the heading die and of the 3 heading die, and associated parts, taken on the line 55 of FIG. 4, and

FIG. 6 is a diagrammatic view of the hydraulic operating system for the holding jaw and the heading dies.

Referring in detail to the drawings, the frame of our improved heading apparatus comprises -a base 10, which has rigidly secured thereto the upstanding frame members 11 and 12. Extending between the upstanding frame members 11 and 12 are horizontal bars 14, which are provided with threaded ends 15 that are provided with internally threaded collars 16 for clamping the bars 14 in position on the frame members 11 and 12, said collars being located in position by pins 13. Slidably mounted on the bars 14 is a crosshead 17.

A cylinder head 18 of a hydraulic cylinder having the cylindrical body portion 19 is fixed to the wall 11 by means of headed securing elements 20. The cylinder head 18 and a cylinder head 21 are secured in fluid tight relation with the cylindrical body portion 19 by means of the bolts 22 that extend through the head 18 and have nuts 23 thereon engaging the threaded ends thereof extending beyond the head 21. The cylinder head 21 has a passage therethrough for a piston rod 25, which is mounted on the piston operating in the cylinder 19 and which has a screw-threaded connection at 27 with the crosshead 17, suitable means being provided for locking the crosshead 17 in adjusted position on the piston rod 25.

Mounted on the crosshead 17 is amovable clamping jaw 29, which is of an elongated character and which has a convexly curved surface 24 seated in a concave groove 28 in a bar 30 secured to the crosshead 17 by headed screw-threaded fastening elements 31. A stationary clamping jaw 32 is mounted on the upstanding frame member 12 in a similar manner by means of similar fastening elements 33. Said jaws 29 and 32 are similar in character, the jaw 32 being mounted on a bar 34 and having a convex surface 24 engaging in a concave groove 28 in said bar. Keys 36 hold said jaws in longitudinal alignment. The jaws have longitudinal grooves 37 of such size and character that when a wire 38 is seated in the two grooves 37 of the jaws 29and 32 the flat faces of the jaws will be slightly out of engagement so that the clamping pressure 'will be exerted entirely on the wire 38. Said jaws 29 and 32 are elongated in a direction transverse to the movement of the jaw 29 and the grooves 37 in said jaws are in transverse alignment with each other, suitable means being provided for properly aligning the grooves with each other.

The upstanding wall 12 has an extension 41 to which a hydraulic cylinder 42 is secured, said cylinder 42 being 7 cylinder heads 40.

A piston rod 44 extends from the piston in the cylinder 42 and has an enlargedhead 45 thereon, on which the heading die 46 is mounted by means of a threaded coupling member '47 engaging in the head 45 and screwthreadedly receiving the threaded shank 48 on the die 46. The coupling 47 is slidably mounted in a bushing 52 V mounted in the bracket 49 secured to the frame member 12 by fastening elements having heads 50 and threaded ends 50" engaging in threaded openings in frame member 12. The enlargement 45 limits movement of the die 46 in a heading direction by engagement with the bracket 49. Said die has a spheroidal recess 51 therein, which receives the projecting end portion of the wire in the grooves 37 and serves to form a head thereon in cooperation with the recessed portions 51' of the jaws 29 and 32 (see FIG. 5). a

A pump driven by the motor 53 is mounted in a tank 54, said tank-containing hydraulic fluid and said pump pumping said hydraulic fluid to the hydraulic cylinders in a manner to be described below. The jaws 29 and 32 are provided with a plurality of aligned bores 55 and 56 in which the pins 57 are mounted. Said pins are thus located immediately below the grooves 37 so that a wire 38, if placed on the pins 57, will be in alignment with the grooves 37 so as to readily enter the same upon the jaw29 moving into cooperative relation with the jaw 32. The pins have screw-threaded ends 58 secured in the bores 55 and are slidably mounted in the bores 56 which have enlarged ends 59.

Referring now to FIG. 6, the cylinder 19 is shown as being provided with a piston 60, from which the piston rod 25 extends, the movable jaw 29 being shown diagrammatically as. secured to said piston rod 25 and the stationary jaw being shown diagrammatically at 32. A piece of wire 38 is shown as being mounted in the jaw 32, the jaw 29 being in a position in spaced relation from the stationary jaw 32. A conduit 61 extends into the cylinder 19 adjacent one end thereof and the conduit 62 extends into the cylinder 19 adjacent the other end thereof. The cylinder 42 is shown as having a piston 63 therein, from which the piston rod 45 extends, which is provided with die 46, the die shown in the diagrammatic view of FIG. 6 as being an integral part of the piston rod, although it is to be understood that the structure of the piston rod and the die and the connection between the same are shown in FIG. 5.

A pump 64 is driven by the motor 53' shown in FIG. 1 and has an inlet connection 65 extending from the tank 54 to the pump. The outlet connection of the pump'is connected with a conduit 66, from which branch conduits 67 and 68 extend. The branch conduit 67 is provided with a venturi 69 and extends to a pressure responsive switch 70, which is provided with a movable contact member 71, said switch having a chamber 72 provided with a piston 73, from which the rod 74 extends to a head 75 that is adapted to engage the movable contact member 71. Manual means, such as a foot pedal 76, is provided for manually moving the switch to the position shown in FIG. 6. It is, of course, to be understood that the actuating member 75 is electrically'insulated in a suitable manner from the movable contact member 71, and that the operating member 76 is similarly electrically insulated from the contact member 71. A spring 77 normally holds the piston 73 in the position'shown in FIG. 6.

The conduit 66 leads into a passage 78 in the body portion of the solenoid valve 79, which is provided with a suitable winding for receiving the core of the valve-to hold it in the position shown in FIG. 6 when the winding is energized, a spring 80 being provided for moving said a solenoid valve to an alternative position, the solenoid,-

when energized, acting to compress the spring so that upon de-energization of the solenoid the spring 80 will sage 78. A passage 86 leads from the passages 83and 84 and has a conduit 87 connected therewith.

A conduit 88 leads from the passage 81 and the conduit 61 is connected with the passage 82. A branch conduit 89 extends from the conduit 61 to a sequence valve f 90 and a conduit 91 extends fi'om said sequence valve to one end of the cylinder 42. A passage 92 extends to the inner end of a chamber 93 in which a piston 94 is slidably mounted, said piston having a reduced extension 94 slidably mounted in the portion 92 of the passage 92. A rod 95 connects the piston 94 with a valve member 96, which is provided with a spring 97 engaging a movable stop member 98 provided withan adjusting screw 99. It will be obvious that the pressure of the spring 97 can be adjusted so that at a predetermined pressure the piston 94 will be moved downwardly to the position shown'in FIG. 6 from a position adjacent the upper end wall of the chamber 93 so as to move the valve member 96 to the position shown in FIG. 6 from one in which it is located in the passage 100 that is provided between the chamber 101, into which the branch conduit 89 extends and the chamber 102, with which the conduit 91 connects. Accordingly the sequence valve 90 will operate to connect the conduit 91 with the branch conduit 89 only after the pressure in the conduit 61 and cylinder 19 has reached a predetermined amount, determined by the adjustment of the adjusting member 99 of the spring 97, to overcome the spring pressure and move the parts of the valve 90 to the position shown in FIG. 6. The spring 97 is located in a chamber 103 below the valve 96, and it will be seen that when the valve member 96 is located in the passage 100 the chamber 102 and the chamber 103 will be connected with each other. Also a check valve 104 is provided, which engages a seat leading to the passage 105 and is held against said seat by the spring 106. When the valve member 96 is in the position shown in FIG. 6 the pressure created in the passage 102 will unseat the valve 104 and provide for direct communication between the chamber 101 and the chamber 102.

A conduit 107 extends from the chamber 103 to the tank 54 and the conduit 88 extends from the conduit 107 to the passage 81 in the valve 79. Valve portions 108, 109 and 110 are provided in the solenoid valve 79. A branch conduit 111 extends from the conduit 107 to the conduit 87 and a branch conduit 112- extends from the conduit 111 to a valve 113, a passage 114 being provided in said valve that is connected with the conduit 112 and a passage 115 being provided in said valve leading from the conduit 87. The passage 115 is provided with a seat for the valve 116, which is provided with a piston 117 that operates slidably in the passage 118 and is provided with a guide pin 119 and with a compression spring 120 that is mounted between the bottom wall of a chamber 121 and the piston 117.

Extending from the cylinder 42 is a conduit 122, which connects with the conduit 62, the conduit 62 leading into the bottom of a pressure tank 123, which contains a body of hydraulic fluid 124 and an air chamber 125 above said body of hydraulic fluid 124.

One of the line wires 126 extending from a suitable source of electric current extends to one end of the winding of the solenoid valve 79. The other line conductor 127 extends to the movable contact member 71 and a conductor 128 extends from the stationary contact 129, with which the movable contact is adapted to engage, to the other end of the solenoid winding of the valve 79. When the operating means 76 is actuated the movable contact member 71 completes the circuit to the solenoid winding of the valve 79 and moves the valve int-o the position shown in FIG. 6 against the compression of the spring 80. With the valve in the position shown in FIG. 6, the conduit 66 extending from the pump is connected with the conduit 61 leading to the cylinder 19. The pump 64 is connected with the chamber 130 in the valve 113 through the branch conduit 68, and thus the pressure created by the pump 64 acts on the upper face of the piston 117 against the action of the spring 121, but the valve -116 is not unseated until the pressure in the chamber 130 is great enough to overcome the pressure of the spring 121.

The chamber 101 in the valve 90 is also supplied with hydraulic fluid under pressure from the conduit 61 through the conduit 89 when the solenoid valve 79 is in the position shown in FIG. 6. With the solenoid valve 79 in the position shown in FIG. 6 the conduit 87 is connected through passages 81 and 83 with conduit 107 through branch conduit 111 and conduit 112 leading to under side of piston 117 is also connected with conduit 107, the fluid in all said conduits being under atmospheric pressure. Accordingly all of the passages and chambers of valve 113 except chamber 130 will be under atmospheric pressure and the chamber 130 will contain hydraulic fluid under the pressure of that in conduits 66 and 61. As the pressure builds up behind the piston 60 it will move the jaw 29 toward jaw 32 and after said pressure reaches that desired for firmly clamping the wire 38 between the jaws 32 and 29 the pressure exerted on the end of reduced extension 94' will move valve 96 from a position in the passage 100 to the position shown in FIG. 6. Hydraulic fluid will then be supplied to cylinder 42 through conduit 91 to move the piston 63 to the left and move the die 46 into position to cooperate with die portions 51' to form the head 131 on the wire 38 (FIG. 5).

At the time the dies reach the position shown in FIG. 5 a maximum pressure will be reached in the conduit 66 by action of the pump 64. This maximum pressure is transmitted to the pressure responsive switch 70 through conduit 67 and venturi 69 and the valve 113 through conduit 68. However, due to the restriction in venturi 69 the valve 116 will be unseated before the switch 70 is operated to return the movable contact to open circuit position. Accordingly the valve 116 will be unseated before the solenoid valve 79 moves under the action of the spring to its alternate position in which the conduit 61 is connected with conduit 87 through passages 82, 84 and 86, and conduit 66 is connected with conduit 88 through passages 78 and '81. The pump 64 will then pump the hydraulic fluid in a closed circuit between the same and tank 54 and the pressure thereof will drop to only slightly above atmospheric.

As the pistons 60 and 63 are moved toward the ends of the cylinders 19 and 42 with which the conduits 62 and 122 are connected the hydraulic fluid ahead of the pis ton is transferred to the closed tank 123, increasing the amount of hydraulic fluid therein and compressing the air in the space 125. As the pressure in the conduit 61 drops toward atmospheric because of the connection of the conduit 61 with open tank 54 through solenoid valve 79, after de-energization thereof, the hydraulic fluid under pressure in tank 123 acting on the pistons returns them to their retracted position shown in FIG. 6. As the pistons move back to this position the hydraulic fluid that had been supplied thereto through conduit 61 is returned to tank 54 through conduits 87, 111 and 107 from cylinder 19. The pressure of the hydraulic fluid in passage 92 having dropped the valve 96 will have moved back into passage 100, however, as pressure in the chamber 102 is greater than in passage 101, check valve 104 will open, if the pressure is suficient to overcome pressure of spring 106, and movement of valve 96 will open the passage between chamber 102 and 103 and thus connect conduit 91 with the open tank 54 through conduit 107. The pistons and solenoid switch thus return quickly to their inoperative positions and another cycle of operations thereof can be initiated by actuation of the operating member 76, the pressure switch 70 and pressure valve 113 having returned to the position shown in FIG. 6 as soon as the pressure in the conduit 66 dropped to near atmospheric due to connection of said conduit with the open tank 54.

It will be noted that the stroke of the die 46 is such that when it is in a retracted position it will act as a stop to limit movement of the wire 38 endwise of the jaw 32.

What we claim is:

1. In a heading machine, a pair of horizontally elongated work clamping jaws having longitudinally extending smooth surfaced open ended concave work receiving grooves in the side'faces thereof, means for moving one of said jaws into position relative to the other jaw and holding said jawin position to hold said work against endwise movement relative to said jaws, said jaws having work supporting members extending transversely across said jaws having supporting surfaces aligning with corresponding longitudinal edges of said work receiving grooves to align the work with said grooves and engaging said jaws to guide said movable jaw in its movements with respect to said other jaw, a heading die having a retracted position and a projected position, said die acting as a stop in its retracted position to limit endwise projection of the its retracted position toward its projected position only.

after said jaw has reached its work clamping position, the ends of said jaws nearest said heading die each having a die portion cooperating with said heading die.

2. In a machine for heading a wire, an elongated stationary jaw having a longitudinal wire receiving groove therein, an elongated movable jaw having a longitudinal wire receiving groove therein aligned with said first groove, hydraulic means for moving said movable jaw into and out of clamping position relative to said stationary jaw, means controlling'the supply of hydraulic fluid to said hydraulic means to move said movable jaw into clamping position and hold said jaw in said position, a recessed heading die at one end of said jaws, said die having a flat end face, said grooves terminating in spaced relation to said end of said jaws, said jaws having transversely aligned fiat end faces engaging with the flat end face of said die to limit heading movement thereof and being recessed at said end thereof beyond the ends of said grooves to provide a die portion in said flat end faces cooperating with said recessed die, and hydraulic means for moving said die into and out of heading position, said controlling means including hydraulic pressure controlled means for supplying hydraulic fluid to the means for moving said die toward heading position after a predetermined holding pressure has been established in said hydraulic jaw moving means.

3. In a machine for heading a wire, a stationary jaw, a movable jaw, hydraulic means for moving said movable jaw into clamping position relative to said stationary'jaw comprising a hydraulic cylinder and a piston operating therein, means controlling the supply of hydraulic fluid to said hydraulic means to move said movable jaw into clamping position and hold said jaw in said position, a heading die, hydraulic means for moving said die into heading position comprising a hydraulic cylinder and a piston operating therein, hydraulic pressure actuated means controlling the supply of hydraulic fluid to said hydraulic means to successively supply hydraulic fluid to said first hydraulic means to move said jaw into clamping position, increase the pressure in said hydraulic means to a predetermined clamping pressure and supply hydraulic fluid to said second means to move said die into heading position, and means for supplying hydraulic fluid simultaneously to both said hydraulic means to move said jaw out of clamping position and said die out of heading position, comprising a pressure tank, containing a body of air in the upper portion thereof and hydraulic fluid in the lower portion thereof, said tank having an inlet connection adjacent the bottom thereof and conduit means connecting both said cylinders with said inlet connection, said tank being closed except for said inlet connection and said inlet connection providing a sealed connection between said tank and said cylinders, said controlling means comprising a solenoid valve controlling supply of hydraulic fluid to said pressure actuated means, a conduit supplying hydraulic fluid to said solenoid valve, a switch controlling the position of said solenoid valve, hydraulic pressure responsive switch opening means, a pressure responsive relief valve connected with said last mentioned conduit and passage restricting means interposed between said switch opening means and said last mentioned conduit, whereby said switch opening means opens said switch after said relief valve has moved to pressure relieving position. 1 t 4. In a machine for heading a wire, a horizontallyelongated stationary jaw having a smooth surfaced longitudinalwire receiving groove of uniform bore in the side thereof, a horizontally elongated movable jaw having a smooth surfaced longitudinal wire receiving groove of uniform bore in the side thereof aligned with and of the same cross section as said first groove, means for moving said movable jaw into and out of clamping position relative to said stationary jaw, said means moving said movable jaw into clamping position and holding said jaw'in said position to hold said work against endwise movement relative to said jaws, a heading die mounted for movement 7 toward and away from one end of said jaws, said heading die having a flat face having a recess therein, guiding' means for said heading die for aligning said recess with said grooves in said jaws in their clamping position, and said jaws having transversely aligned flat end faces extending transversely to said grooves engaged by saidrflat end face of said heading die to limit the heading movement of said die, said flat end faces of said jaws having recesses therein extending from the adjacent ends of said grooves and aligned therewith and cooperating with said recess in said die to form said head and means for moving said heading die'into heading position after a predetermined holding pressure has been applied to said movablejaw by said jaw moving means, said die when in retracted position constituting wire stop means to limit endwise projection of said wire beyond said grooves.

5. In a heading machine, a pair of work clamping jaws, hydraulic means for moving one of said jaws into work clamping position relative to the other jaw and holding said jaw in said position, comprising a hydraulic cylinder and a piston operating therein, a heading die, hydraulic means for moving said die into heading position, compriscylinders at one end thereof comprising means for supply-.

ing said fluid to said last mentioned hydraulic means to move said die toward heading position only after said jaw has reached its work clamping position, and means for returning said holding jaw and said heading die to inoperative position, comprising hydraulic pressure actuated means for relieving the pressure on said hydraulic fluid supplied to said ends of said cylinder, a pressure tank containing a body of air and hydraulic fluid and conduit means connecting said pressure tank with both said hydraulic means at the other ends of said hydraulic cylinders, said tank being closed except for said means to provide a sealed chamber of variable capacity including the portions of said cylinders between said pistons and said other ends of said cylinders, said conduit means and said pressure tank.

6. In a heading machine, a pair of work'clamping jaws, '7

hydraulic means for moving one of said jaws into work clamping position relative to the other jaw and holding said jaw in said position, comprising a hydraulic cylinder and a piston operating therein, a heading die, hydraulic means for moving said die into heading position, comprising a hydraulic cylinder and a piston operating therein, means for supplying hydraulic fluid under pressure to said cylinders at one end thereof comprising means for supplying said fluid to said last mentioned hydraulic means to move said die toward heading position only after said jaw has reached its work clamping position, and means for returning said holding jaw and said heading die to inoperative position, comprising hydraulic pressure actuated means for relieving the pressure on said hydraulic fluid UNITED STATES PATENTS 757,409 4/1904 Olson 10-15 2,113,110 4/1938 Ernst et al 72-453 2,932,951 4/1960 Ottestad et al. 91-5 3,186,169 6/1965 Hauser 915 WILLIAM W. DYER, JR., Primary Examiner. GERALD A. DOST, Examiner. 

1. IN A HEADING MACHINE, A PAIR OF HORIZONTALLY ELONGATED WORK PLANNING JAWS HAVING LONGITUDINALLY EXTENDING SMOOTH SURFACED OPEN ENDED CONCAVE WORK RECEIVING GROOVES IN THE SIDE FACES THEREOF, MEANS FOR MOVING ONE OF SAID JAWS INTO POSITION RELATIVE TO THE OTHER JAW AND HOLDING SAID JAW IN POSITION TO HOLD SAID WORK AGAINST ENDWISE MOVEMENT RELATIVE TO SAID JAWS, SAID JAWS HAVING WORK SUPPORTING MEMBERS EXTENDING TRANSVERSELY ACROSS SAID JAWS HAVING SUPPORTING SURFACES ALIGNING WITH CORRESPONDING LONGITUDINAL EDGES OF SAID WORK RECEIVING GROOVES TO ALIGN THE WORK WITH SAID GROOVES AND ENGAGING SAID JAWS TO GUIDE SAID MOVABLE JAW IN ITS MOVEMENTS WITH RESPECT TO SAID OTHER JAW, A HEADING DIE HAVING A RETRACTED POSITION AND A PROJECTED POSITION, SAID DIE ACTING AS A STOP IN ITS RETRACTED POSITION TO LIMIT ENDWISE PROJECTION OF THE WORK ENGAGED BY SAID JAWS BEYOND THE GROOVES IN SAID JAWS TOWARD SAID DIE, AND MEANS FOR MOVING SAID DIE FROM ITS RETRACTED POSITION TOWARD ITS PROJECTED POSITION ONLY AFTER SAID JAW HAS REACHED ITS WORK CLAMPING POSITION, THE ENDS OF SAID JAWS NEAREST SAID HEADING DIE EACH HAVING DIE PORTION COOPERATING WITH SAID HEADING DIE. 